Feeder crusher

ABSTRACT

A mobile, low-profile feeder-crusher machine for receiving, crushing and feeding freshly mined coal to a stationary conveyor system includes a rigid frame supporting a rotary crusher shaft and supporting an endless conveyor for delivering coal to the crusher shaft and for removing crushed coal therefrom. The drive system for the crusher shaft is mounted on the frame and includes a hydraulic pump driven by an electric motor, a hydraulic motor driven by the pump, a planetary gear reduction driven by the hydraulic motor and having a carrier output driving the crusher shaft, and a flywheel rotatable with the input of the reduction gear assembly.

.Iadd.In accordance with the provisions of 35 U.S.C. 120 the benefit ofthe filing date is claimed of patent application Ser. No. 746,819,Feeder-Crusher, Filed Dec. 1, 1976, now U.S. Pat. No. 4,073,445, theoriginal of this reissue application, through its copending continuationapplication, Feeder Crusher, Ser. No. 860,735, Filed Dec. 13, 1977 nowabandoned. .Iaddend.

This invention relates to .[.low-profile feeder.]. crushers for use in.[.low-clearance coal.]. mines and in particular to.Iadd.feeder-crushers having .Iaddend.improvements in the drive systemfor rotating the crusher shaft .[.so as to obtain more effectivecrushing without adding any appreciable weight or height to themachine.]..

BACKGROUND OF THE INVENTION

In coal mines where the coal exists in the form of relatively thinlayers or seams it has long been the practice to employ coal-handlingequipment which has a sufficiently low profile or height to beaccommodated in the low-clearance areas formed as the coal is mined. Onewidely used mining technique includes the use of so-calledfeeder-crusher machines which .[.rereceive.]. .Iadd.receive.Iaddend.freshly mined coal from a mining machine or haulage vehicle,crush the coal to a smaller more manageable size and feed it to aconveying system for removal from the mine.

Current feeder-crushers are mobile low-profile machines having ahorizontally elongated hopper-like body fitted intermediate its endswith a rotary crusher. Horizontal transverse flights carried by a pairof endless chains continuously move along the floor of the body and inso doing they urge coal from the receiving end of the body to the rotarycrusher and move the resulting crushed coal away from the crusher towardthe rear end of the body where it is discharged. The discharged coalfalls on to an endless conveyor which may be one of a series leading outof the mine. A typical feeder-crusher will not exceed about four feet inheight in order that it can be maneuvered into a low-clearance space.

The body and the rotary crusher are interconnected with rigid framemembers to form a unitary structure which supports the components of thepower system required for operation of the machine. Typically, theentire structure is supported on a crawler-type propelling unit operatedby a hydraulic or in some cases electric motor. Typically the powersystem includes an electric motor and a hydraulic pump driven by themotor. Electric current is supplied to the motor by cables leading intothe mine. The pump supplies pressurized hydraulic fluid for operatingthe crawler unit and for operating a separate hydraulic motor whichdrives a speed reduction unit having its output connected to the rotarycrusher shaft.

The rotary crusher is typically of the hammer mill or impact type inwhich a horizontal rotating shaft is provided along its length with aplurality of radial striker arms or hammers. The shaft is disposedtransversely of the body of the machine, and as the coal is urged intothe hammer circle between the shaft and the floor of the machine, bymeans of the moving flights, it is struck and crushed by the strikerarms. The coal passes through the hammer circle only once, so that thearms are continually acting on fresh coal.

Since all of the material received by a feeder-crusher passes throughthe crushing assembly, the crushing of the coal must be carried outcontinuously and at a high rate if the machine is to operateeffectively. The crusher is the limiting feature of the machine, becausethe conveyor system can be constructed to handle essentially any inputload. Therefore, any increase in the ability of the crusher to handle agreater throughput increases the capacity of the machine. In addition itis important to reduce down-time due to jamming of the crusher orbreakage of any part of the crusher drive system. Inherently the coalwill include rock in varying amounts and the rock being harder and moreresistant to crushing will sometimes tend to wedge between the floor ofthe machine and the breaker arms or will create very high strains in thedrive system. The result can be jamming of the crusher and/or shearingof a shear pin which is typically inserted between the crusher shaft andthe output shaft of the drive system. The machine is then out ofoperation until the fault has been remedied, and during this timeloading of coal into the receiving end of the machine must stop, therebyreducing production.

The solution of the problems relating to increasing the throughput of acrusher system in a feeder-crusher and to reducing down-time resultingfrom jamming or breakage do not lie merely in increasing the size andpower of the crusher system. The principal reason for this is that it isnot practical or economical to install heavier and larger drivecomponents and/or heavier and larger crusher shafts. As previously notedthe height of the machine .[.must.]. .Iadd.should .Iaddend.be limited toabout four feet; current construction techniques and the powerrequirements of the machines result in essentially all useable spacebeing occupied. Further, the length, width and weight of the machinesare limited as a result of the limited space in which the machines mustoperate.

SUMMARY OF THE INVENTION

The broad object of the invention is to improve the performance of arotary impact type crusher, in terms of the ability of the crusher toprocess material at a greater rate and in terms of reduced jamming,without adding any appreciable size, weight of expense to the system..[.It is apparent from the nature.]. .Iadd.The performance .Iaddend.ofan impact type crusher .[.that its performance.]. can be improved byincreasing the torque .[.delivered by.]. .Iadd.available at .Iaddend.thecrusher shaft .[., but the most straightforward means for doing this,that is, replacing the.]. .Iadd.by using a .Iaddend.motor .[.with one.].of greater power, .[.lies outside the constraints of the stated object.It is known, also, that connecting a flywheel to a rotating shaft willeffect high torque, and it is conventional in a number of environmentsto provide.]. .Iadd.or .Iaddend.a flywheel .[.on the work shaft of amachine, that is,.]. on the relatively low speed output of whateverspeed reduction system is driven by the power source.

.[.In the case of a feeder-crusher machine for use in low clearancemines this modification is not.]. .Iadd.Such modifications are notusually .Iaddend.feasible.Iadd.. .Iaddend..[.because calculationsreadily show that in order.]. .Iadd.For example, .Iaddend.to increasethe torque significantly a flywheel connected with the crusher shaftmust be extremely large and heavy. .[.For example, calculations.]..Iadd.Calculations .Iaddend.for a typical crusher shaft rotating at 90rpm show that to effect a 100% increase in torque a flywheel 10 feet indiameter and weighing 2100 pounds is required.

The present invention .[.is based primarily on providing.]..Iadd.provides .Iaddend.a flywheel .[.on.]. .Iadd.attached to.Iaddend.the input of the speed reduction system and .[.secondarily onthe selection of.]. .Iadd.a suitable speed reducing system having arigid transmission characteristic, such as .Iaddend.a planetary gearsystem .[.as the speed reduction system.].. .[.By connecting.]..Iadd.Because of the higher speed of rotation of .Iaddend.a flywheel.[.to rotate with.]. .Iadd.on .Iaddend.the input of the speed reductionsystem .[., that is, to rotate at high rotational speed relative to themore slowly rotating crusher shaft.]. .Iadd.and the resultingexponential increase in stored energy .Iaddend.it is possible to achievea significant increase in the torque .[.of.]. .Iadd.available to.Iaddend.the crusher shaft with a flywheel of .[.small.]. .Iadd.muchsmaller .Iaddend.size and mass. For example, to achieve theaforementioned 100% increase in .Iadd.available .Iaddend.torque aflywheel connected to the input shaft of the speed reduction system atthe stated crusher shaft speed of 90 rpm need by only 20 inches indiameter and weigh only 228 pounds .[. , assuming.]. .Iadd.with.Iaddend.an input speed of 675 rpm. This increased .Iadd.available.Iaddend.torque .[.has an exceptional ability to increase.]..Iadd.increases .Iaddend.the throughput of the crusher and .[.toreduce.]. .Iadd.reduces .Iaddend.the tendency to jam. The crushingaction of the arms or hammers on the coal and rock results from acombination of direct impact of the crusher arms with chunks of materialand pinching of the chunks between the bottom of the body of the machineand the crusher arms. Since the proportion of rock and the size of therock and coal in the material passing to the crusher vary continuously,there is a continuous variation in the stresses applied to the crushershaft. Further, large chunks cannot pass through the crusher until theyhave been reduced in size, and as a consequence if a chunk does notbreak it will jam the crusher, causing damage to the latter or shearingof the shear pin. If the impact and pinching forces can be increasedessentially instantaneously with increases in resistance to crushingthen the crusher shaft will be much less apt to jam. This is.[.precisely.]. the effect .[.which is.]. produced by .[.increasing thetorque on the crusher shaft by means of.]. .Iadd.the relatively.Iaddend.low-mass.Iadd., .Iaddend.rapidly rotating flywheel arrangementof the present invention.

The .[.increased torque produced by the.]. flywheel arrangement of thepresent invention may, however, create a problem in that the torque isapplied through the .Iadd.rigid .Iaddend.speed reducer .[.,.]. ratherthan directly to the massive crusher shaft. .[.It has been establishedby calculation that the increased.]. .Iadd.The .Iaddend.torque.[.supplied by.]. .Iadd.available with .Iaddend.the previously described228 pound flywheel connected to the input of the typical gear type speedreducer in current use on feeder-crusher machines .[.will.]. .Iadd.can.Iaddend.overstress the gears to the point of destruction during use..[.The solution to this.]. .Iadd.This .Iaddend.problem .[.does not liein replacing the existing reducer with.]. .Iadd.may be solveable byusing .Iaddend.a more massive .[.one.]. .Iadd.speed reducer .Iaddend.ofthe same design, .[.because this is inconsistent with the requirement ofthe invention that the.]. .Iadd.but this would prohibitively increasethe .Iaddend.weight and size of the overall feeder-crusher machine.[.must not be increased to any appreciable extent.]. .Iadd.and itsresulting cost.Iaddend.. .[.Rather, the problem is solved by replacingthe typical speed reducer with.]. .Iadd.With this invention .Iaddend.aplanetary gear reducer .Iadd.readily .Iaddend.capable of withstandingthe additional torque .[.. This replacement does not result in.]..Iadd.is used without creating .Iaddend.an increase in size or weight ofthe overall machine.Iadd.. .Iaddend..[.because the planetary system hasa high strength to weight ratio. This aspect of a.]. .Iadd.A.Iaddend.planetary system .[.is exceedingly well.]. .Iadd.may beparticularly .Iaddend.adapted for the purpose of the invention.[.because.]. .Iadd.by transmitting .Iaddend.the stresses .[.appliedto.]. .Iadd.of .Iaddend.the system .[.can be readily tranmitted.]. tothe already massive frame of the machine. In using a planetary system ina speed-reducing mode the ring gear is locked .[.,.]. .Iadd.byconnecting .Iaddend.the input .[.is connected.]. to the sun gear and theoutput .[.is connected.]. to the carrier.[.. In the system contemplatedby the present invention.]. .Iadd.and locking .Iaddend.the ring gear.[.need not ever rotate and.]. .Iadd.which .Iaddend.may therefore be.Iadd.made .Iaddend.a permanent part of the frame. While a simpleplanetary system will suffice a compound system may also be employed.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT

The invention will be further understood from the following moredetailed description taken with the drawings in which:

FIG. 1 is a schematic elevational view of a feeder-crusher machine;

FIG. 2 is a schematic plan view of the machine of FIG. 1;

FIG. 3 is a sectional view on an enlarged scale of the drive system forthe crusher; and

FIG. 4 is an end view of the drive system for the crusher.

FIGS. 1 and 2 illustrate a feeder-crusher machine 10 which includes.[.as its major parts.]. a receiving section 12, a crusher section 14and a discharge section 16. The receiving section 12 is a hopper-likestructure open at both ends and at the top and .[.being.]. formed.[.of.]. .Iadd.by .Iaddend.side walls 18 and 20 and a bottom wall 22,the latter extending the length of the machine and thereby forming thebottom wall of the crusher section 14 and of the discharge section 16.The discharge section 16 includes side walls 24 and 26 and lateralsupport shelves 28 and 30 for supporting the components of the powersystem, such as an electric motor 32, hydraulic pumps 34 and a reservoir36 for the hydraulic system. In the interest of simplicity theconnections between the pumps 34, the various hydraulic motors and thereservoir 36 are not shown.

The three sections 12, 14 and 16 together with various frame membersform a unitary rigid body which is supported from the ground by twotransversely-spaced endless-thread crawler units 38. The connectionbetween each crawler unit 38 and the body is a tube and shaft-likeassembly 40 having a tubular end 42 which is fixed to the frame of theunit 38 and a shaft end 44 which is bolt-connected to the body at 46 forlimited rotation about a transverse horizontal axis. A hydraulic pistonand cylinder unit (not shown) connected between the body and the frameof the crawler unit determines the angular position of the body relativeto the crawler units 38. The drive system for each crawler unit 38includes a hydraulic motor 48 which receives pressure fluid from one ofthe pumps 34.

The crusher section 14 includes a rigid horizontal shaft 50 mountedtransversely in the machine and provided with a plurality of radialbreaker arms 42 or hammers. The circle 54 defined by the outer ends ofthe arms 52 during rotation of the shaft 50 lies slightly above thebottom wall 22 of the machine so that coal and rock will be crushed inpassing through the space between the circle 54 and the wall 22. Duringoperation of the machine coal and rock are urged into this space by aseries of longitudinally spaced apart transverse flights 56 which aremoved from left to right along the upper surface of the bottom wall 22by .[.means of.]. a pair of spaced-apart endless chains the upper run ofwhich is illustrated at 58. The chains 58 are looped over sprockets 60and are driven by hydraulic motors 61 powered from one of the pumps 34.The crushed material is then carried by the flights 56 from the crushersection 14 to the right hand end of the machine.

All of the above is generally conventional in feeder-crusher machines..[.According to the present invention the.]. .Iadd.The .Iaddend.drivesystem for the crusher shaft 50 includes a planetary gear reduction unit62 having a low speed output driving the crusher shaft 50 and having ahigh speed input carrying a flywheel 68. The input shaft 66 also carriesa secondary input gear 70 which meshes with a primary input gear 72carried by the shaft 73 of a hydraulic motor 74 driven by one of thepumps 34.

As seen in FIG. 3 the planetary gear unit 62 includes a sun gear 76carried on the input shaft 66 and four planet gears 78 meshing with thesun gear 76 and with an internally toothed ring gear 80. An end 64 ofthe crusher shaft 50 is carried by a planet gear carrier 82. The ringgear 80 is fixed against rotation, preferably by being made unitary withthe body and/or frame of the machine.

In use the machine is propelled into a .[.low clearance.]. mine area bymeans of the crawler units 38, under the control of an operator.Electric current for the motor 32 is supplied to the machine by a cable(not shown). The control valves for the various hydraulic motors arecarried by the machine but are not shown inasmuch as they .[.may be.]..Iadd.are .Iaddend.conventional features of a feeder-crusher. When themachine has been properly located, the sprocket motors 61 and thecrusher motor 74 are set in motion and coal is loaded into the receivingsection 14. The moving flights 56 urge the uncrushed coal into thehammer circle 54 of the crusher and then urge the coal crushed by thebreaker arms 52 into the discharge section 16.

The system of flights 56 and chains 58 can be designed and constructedto transport the uncrushed and crushed coal at essentially any practicalrate and the ability of the crusher is therefore the limiting feature ofthe machine's throughput. As described earlier .[.this limiting featureis overcome to a large extent by providing.]. .Iadd.by connecting.Iaddend.a flywheel 68 .[.at.]. .Iadd.to .Iaddend.the high-speed input.Iadd.shaft .Iaddend.of the speed reducer .[.so that the.]. torque.[.applied.]. .Iadd.available .Iaddend.to the crusher shaft 50 is.[.amplified by the rapidly rotating.]. .Iadd.significantly increasedfor a given .Iaddend.flywheel .[.68.].. The .[.amplification.]..Iadd.increase .Iaddend.is, of course, .[.proportional to.]. .Iadd.afunction of .Iaddend.the weight .Iadd.of .Iaddend.and .Iadd.the squareof the .Iaddend.speed of .Iadd.rotation of .Iaddend.the flywheel 68, andfor a given crusher the weight of the flywheel to be used will beselected on the basis of the desired .[.increase in.]. torque, subjectto the space available for the flywheel.Iadd., the speed of rotation ofthe input .Iaddend.and the ability of the crusher to withstand.[.higher.]. stresses. Preferably the flywheel should produce a minimumincrease of 25% in the torque .[.applied to.]. .Iadd.available at.Iaddend.the crusher shaft .[.,.]. over that .[.which is.]. availablewithout the flywheel. The speed reducer is preferably of the planetarygear type because this type of construction is capable of absorbing thehigh stresses which will develop .[.when the amplified torque applied tothe crusher shaft 50 overcomes a resistance which would cause jamming ofthe crusher if the amplified torque was not present.]..

It will be understood that the term flywheel means a discrete body ofrevolution of greater diameter and mass than the shaft on which it iscarried. The flywheel may have its mass concentrated, ring-like, nearits periphery as shown, or it may be a disc of uniform thickness.

What is claimed is:
 1. A feeder-crusher machine for use in low clearancemines comprising an elongated low-profile body supported from the groundon traction means so as to be movable along the ground longitudinally,said body having side walls and a bottom and including, in end-to-endrelationship along the length of the machine, a receiving section, acrushing section and a discharge section; said crushing sectionincluding a rotary crusher shaft mounted transversely in said body andcarrying a plurality of radial breaker arms the outer ends of whichdefine a circle spaced from a wall of the machine; means for urgingmaterial residing on said bottom in said receiving section to the spacebetween said circle and said wall so as to be crushed therein and forurging the resulting crushed material along the discharged section in adirection away from said crusher section; and drive means mounted onsaid body for rotating said crusher shaft, said drive means including aconstant-speedmotor, a mechanical speed reduction unit having a highspeed input driven by said motor, a low speed output driving saidcrusher shaft, a gear system connected between the input and the outputfor rotating the output at a speed proportional only to the speed of theinput and a flywheel connected to rotate with said high speed input tosaid speed reduction unit whereby amplified torque produced by the highspeed flywheel is transmitted through the gear connections in saidreduction unit to the more slowly rotating crusher shaft.
 2. Afeeder-crusher as in claim 1 wherein said speed reduction unit includesa planetary gear set having a sun gear, another gear, planet gearsmeshing with said sun gear and said other gear and a planet carrier,said other gear being fixed to said body, said sun gear being driven bysaid motor and said carrier driving said low speed output. .Iadd.3. Inan impact-type crushing machine: a rotary crusher shaft carrying impactmeans; fixed means against which material is crushed by the action ofthe impact means on the material; a high speed motor; a planetary gearreduction unit having a sun gear, another gear, planet gears meshingwith said sun gear and with said other gear and a planet carrier; meansfixing said other gear against rotation; a first driving connectionbetween said motor and said sun gear, said first driving connectionincluding a flywheel which amplifies the torque supplied through saidmeshing gears to said crusher shaft. .Iaddend. .Iadd.4. A crushermaching having a crusher section; a movable breaker surface within thecrusher section; a means for moving material to the crusher section; arotating power source; and a means for driving the breaker surface fromthe rotating power source comprising: a rigid speed reduction systemhaving a relatively high rotating speed input connected to be driven bythe power source and a relatively low speed output connected to move thebreaker surface, and a flywheel attached to rotate with the inputwhereby the inertial energy of rotation of said flywheel is transmittedthrough the reduction system to the breaker surface. .Iaddend. .Iadd.5.A crusher machine according to claim 4 wherein said machine is a feedercrusher machine. .Iaddend. .Iadd.6. A crusher machine according to claim4 wherein said movable breaker surface is a rotating crusher shaft withbreaker arms mounted on said shaft. .Iaddend. .Iadd.7. A crusher machineaccording to claim 4 wherein said speed reduction system comprises aplanetary gear unit. .Iaddend. .Iadd.8. A crusher machine according toclaim 7 wherein said machine has a frame and wherein said planetary gearunit has a ring fixedly attached to same frame. .Iaddend. .Iadd.9. Acrusher machine having a crusher section; a movable breaker surfacewithin the crusher section; a means for moving material to the crushersection; and a means for driving the breaker surface from a rotatingpower source comprising: a rigid speed reduction system having arelatively high rotating speed input adapted to be driven by a rotatingpower source, a relatively low speed output connected to drive thebreaker surface, and a flywheel attached to rotate with the inputwhereby the inertial energy of rotation of said flywheel is transmittedthrough the reduction unit to the breaker surface. .Iaddend. .Iadd.10. Acrusher machine according to claim 9 wherein said movable breakersurface is a rotating crusher shaft with breaker arms mounted on saidshaft. .Iaddend. .Iadd.11. A crusher machine according to claim 9wherein said speed reduction means comprises a planetary gear unit..Iaddend. .Iadd.12. A crusher machine according to claim 11 wherein saidmachine has a frame supporting its parts and wherein said planetary gearunit has a ring gear fixedly attached to said frame. .Iaddend. .Iadd.13.A crusher machine having a crusher means for crushing material adaptedto be driven by a rotating input; a means for moving material to thecrusher means; a means for rigidly driving the crusher means at arelatively low rotating speed from a relatively high speed of rotatinginput: and a flywheel attached to rotate with the input. .Iaddend..Iadd.14. A crusher machine according to claim 13 wherein said machineis a feeder crusher machine. .Iaddend. .Iadd.15. A crusher machineaccording to claim 13 wherein said crusher means comprises a rotatingcrusher shaft with breaker arms mounted on said shaft. .Iaddend..Iadd.16. A crusher machine according to claim 13 wherein said means fordriving comprises a planetary gear unit. .Iaddend. .Iadd.17. A crushermachine according to claim 16 wherein said machine has a main supportframe and wherein said planetary gear unit has a ring gear fixedlyattached to said frame. .Iaddend. .Iadd.18. A crusher machine having acrusher shaft, a power means for producing a rotating output, a speedreduction means connected to receive the rotating output for rigidlytransmitting said rotating output to the crusher shaft at a reducedspeed of rotation, and a flywheel having a selected mass connected torotate with the rotating output to thereby provide energy. .Iaddend.